RE: Question about ocassional loud/crazy arrow flight.
If I understood Len corectly the lift cord is attached to the cable guard slide?
if this is so i would not use the slide to lift the rest, instead serve the cord into the down power harness and adjust where it comes all the way up only one inch from full draw this should eleminate any contact.
also check your nocking point, if it is too low it will cause the back of the arrow to bottom out on the rest as well.